This is a note to let you know that I've just added the patch titled
ext4: fix xattr shifting when expanding inodes
to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ext4-fix-xattr-shifting-when-expanding-inodes.patch
and it can be found in the queue-4.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From d0141191a20289f8955c1e03dad08e42e6f71ca9 Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@xxxxxxx>
Date: Thu, 11 Aug 2016 11:50:30 -0400
Subject: ext4: fix xattr shifting when expanding inodes
From: Jan Kara <jack@xxxxxxx>
commit d0141191a20289f8955c1e03dad08e42e6f71ca9 upstream.
The code in ext4_expand_extra_isize_ea() treated new_extra_isize
argument sometimes as the desired target i_extra_isize and sometimes as
the amount by which we need to grow current i_extra_isize. These happen
to coincide when i_extra_isize is 0 which used to be the common case and
so nobody noticed this until recently when we added i_projid to the
inode and so i_extra_isize now needs to grow from 28 to 32 bytes.
The result of these bugs was that we sometimes unnecessarily decided to
move xattrs out of inode even if there was enough space and we often
ended up corrupting in-inode xattrs because arguments to
ext4_xattr_shift_entries() were just wrong. This could demonstrate
itself as BUG_ON in ext4_xattr_shift_entries() triggering.
Fix the problem by introducing new isize_diff variable and use it where
appropriate.
Reported-by: Dave Chinner <david@xxxxxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ext4/xattr.c | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1352,11 +1352,13 @@ int ext4_expand_extra_isize_ea(struct in
size_t min_offs, free;
int total_ino;
void *base, *start, *end;
- int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
+ int error = 0, tried_min_extra_isize = 0;
int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize);
+ int isize_diff; /* How much do we need to grow i_extra_isize */
down_write(&EXT4_I(inode)->xattr_sem);
retry:
+ isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
up_write(&EXT4_I(inode)->xattr_sem);
return 0;
@@ -1381,7 +1383,7 @@ retry:
goto cleanup;
free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
- if (free >= new_extra_isize) {
+ if (free >= isize_diff) {
entry = IFIRST(header);
ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize
- new_extra_isize, (void *)raw_inode +
@@ -1413,7 +1415,7 @@ retry:
end = bh->b_data + bh->b_size;
min_offs = end - base;
free = ext4_xattr_free_space(first, &min_offs, base, NULL);
- if (free < new_extra_isize) {
+ if (free < isize_diff) {
if (!tried_min_extra_isize && s_min_extra_isize) {
tried_min_extra_isize++;
new_extra_isize = s_min_extra_isize;
@@ -1427,7 +1429,7 @@ retry:
free = inode->i_sb->s_blocksize;
}
- while (new_extra_isize > 0) {
+ while (isize_diff > 0) {
size_t offs, size, entry_size;
struct ext4_xattr_entry *small_entry = NULL;
struct ext4_xattr_info i = {
@@ -1458,7 +1460,7 @@ retry:
EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
EXT4_XATTR_LEN(last->e_name_len);
if (total_size <= free && total_size < min_total_size) {
- if (total_size < new_extra_isize) {
+ if (total_size < isize_diff) {
small_entry = last;
} else {
entry = last;
@@ -1515,20 +1517,19 @@ retry:
goto cleanup;
entry = IFIRST(header);
- if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
- shift_bytes = new_extra_isize;
+ if (entry_size + EXT4_XATTR_SIZE(size) >= isize_diff)
+ shift_bytes = isize_diff;
else
shift_bytes = entry_size + size;
/* Adjust the offsets and shift the remaining entries ahead */
- ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
- shift_bytes, (void *)raw_inode +
- EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
+ ext4_xattr_shift_entries(entry, -shift_bytes,
+ (void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
+ EXT4_I(inode)->i_extra_isize + shift_bytes,
(void *)header, total_ino - entry_size,
inode->i_sb->s_blocksize);
- extra_isize += shift_bytes;
- new_extra_isize -= shift_bytes;
- EXT4_I(inode)->i_extra_isize = extra_isize;
+ isize_diff -= shift_bytes;
+ EXT4_I(inode)->i_extra_isize += shift_bytes;
i.name = b_entry_name;
i.value = buffer;
Patches currently in stable-queue which might be from jack@xxxxxxx are
queue-4.7/ext4-fix-xattr-shifting-when-expanding-inodes-part-2.patch
queue-4.7/ext4-fix-xattr-shifting-when-expanding-inodes.patch
queue-4.7/ext4-avoid-deadlock-when-expanding-inode-size.patch
queue-4.7/ext4-properly-align-shifted-xattrs-when-expanding-inodes.patch
--
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